Dr. Kohler will undertake three basic approaches to studies of the interrelationship of stroma to mammary epithelial cells: growth, differentiation and angiogenesis. They plan to utilize both cell cultures and in vivo techniques to investigate the specificity and importance of stromal cells on the growth and differentiation of normal and obnormal mammary tissue. The first studies would be directed at eh development of an appropriate cell culture system which would include conventional organ and monolayer cultures, a new system on which Dr. Kohler has been working recently, an the perfused fiber system. The markers to be studied of the cell lines will be growth patterns, precursors incoporation, light microscopy, electron microscopy (EM), hormone receptors, specific cell proteins (casein systhesis) and viral studies.